A. Field of the Invention
This invention relates to a redundant drive system utilizing a plurality of electric motors or motor/gearheads in series.
B. Description of Prior Art
There are many types of apparatus utilizing an electric motor in which repair is difficult if not impossible when the motor fails. Examples are earth orbiting satellites, deeply submerged pumps, etc.
Many inventors have addressed themselves to the problem of utilizing redundant motors so that if a single motor fails another can substitute. Examples of patented art in this general area are U.S. Pat. Nos. 871,193 (E. W. Stull), 2,491,842 (B. A. Wells), 2,356,590 (J. H. Jacobsen), 3,538,413 (H. R. Baylis, et al), and possibly 3,309,588 (D. J. Martin, et al). Even insofar as these patents teach redundant drive mechanisms, each system is deficient in that the connection between the motors is susceptible to single point failure, i.e., each of these prior art designs incorporates a connecting clutch, lever, or some other mechanism which can fail to operate. Obviously if the coupling fails to operate, the fact that a backup motor is available is of little consequence since the backup power cannot be utilized.